Because those people who feel bad completely ignore the other side, Switch users and let's review for a sec the history of this game.
- Announced back in 2015 for PS4, Nintendo 3DS and Nintendo NX
- In 2017 they had the big presentation for Japan release on PS4 and 3DS
- Immediately after the release in Japan they announced the western version for PS4 and PC scheduled for 2018 with additional features including an actual VO (english), 4K resolution support, Draconian Quest, a first person camera option, and other minor changes.
Square Enix specifically said these new extra features were made for western audience on those platforms.
- On April 2018 they finally said a word about the Switch version which was delayed, they were waiting for the updated Unreal Engine version.
Square Enix said they considered the idea of releasing all the versions in the west at the same time but they didn't want PS4 and PC users to wait.
- Switch version was then re-announced at Tokyo Game Show where they gave a glimpse of the new additional contents they were working on (Japanese VO, orchestral music, 16bit mode from the 3DS version adapted, new stories)
1) Switch users had to wait the longest dealing with that weird silence for all these years, despite the game was announced for all platforms from the start.
2) Square Enix gave you extra features compared to the japanese version AND they released the game earlier, otherwise you'd have waited another year.
I'm just sayin', don't be selfish and try to consider all sides here, yes Switch version will get more contents, but you have the chance to play the game earlier and buy it for cheap now. On Square Enix side obviously they have to make sure all these versions can sell well despite the huge gaps in between, exclusive contents are a way to make these appealing.